<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>注册</title>
</head>
<body>
<h1>注册用户</h1>
<form action="http://localhost:8080/servlet/helloServlet"
method="post">
  u: <input type="text" name="username"/><br><br>
  <input type="submit" value="注册用户"/>
</form>
</body>
</html>